This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Work is ongoing to determine the effects of influenza A and respiratory syncytial virus (RSV) virions on human immune effector cells of the innate and adaptive immune lineages. A summary of ongoing results was presented at the 27th Annual Meeting of the American Society for Virology. Experimental results over the previous eight months verified that the continuous human cell lines under consideration demonstrate cytokine production patterns similar to primary human immune cells of their respective lineages in response to known mitogens. Following exposure to either influenza A or RSV virions, both expected and novel modulations of cytokine expression were observed. Human natural killer (NK) cells in particular demonstrated marked immunoregulatory potential in response to virion exposure. Interleukin (IL) 7, osteopontin, and OX40 ligand expression by NK cells was significantly modulated following brief exposure to both virions. Influenza A modulated IL-17A expre ssion and RSV modulated IL-5 and IL-13 receptor alpha expression of human NK cells. These finding add greater detail to our understanding of human immune responses to viral pathogens, and have direct implications for the design of virion-based vaccines and immunotherapies.